Method for the separation of chemically modified rosins and their esters into components



Patented Feb. 20, 1940 OFFICE I ,METHODF OR THE SEPARATION OF CHEMI- =GALLY MODIFIED ROSINSi THEIR, ESTERS INTO COMPONENTS Joseph N. Borglin, Wilmington; Deli, assignor to Hercules Powder Company, Wilmington, Dell, acorporation of Delaware:

No Drawing. Original application August 24', 1937, Serial No. 160,725. Divided and thisa-p plication April 1, 1939, S erial No.265,548-

15' Claims.

This invention relates .to' a method for theseparation of chemically modified resins and their esters intocomponents, andimore particularly the separation of chemically modified r'o'sinsan'd their esters into component's'byf treatment with a selective solvent. 1

Due to the complexity of the chemical structure of" rosin, treatments for the production of chemical modifications practically always result in products which aremixtures of two or more dihydro-rosin. More complete hydrogenation re-, sultsin a mixture of dihydro-rosin and tetra-- hydro-rosin. The production of a product which entirely tetrahydro-rosin has so far proved impossible. The esterification of a hydrogenated rosinv results in a mixture of rosin esters. Likewise, thehydrogenation of rosin esters results in a mixture of ordinary rosin ester and dihydr'orosin ester or a mixture of dihydro-rosin ester and tetrahydro-rosin ester. v

The separation of the chemically different components of the chemically modified rosins has heretofore been practically impossible, and the various commercial products have been complex mixtures of compounds of different chemical structure. No successful method for separating the components of such mixtures has been developed, in spite of the fact that it has been fully realized that such separation would be of' great value from a commercial standpoint, as well as from a scientific standpoint.

Now, I have found that I can separate chemito the art to be selective solvents for the visible and latent color bodies of rosin.

The process in accordance with this invention consistsof treating a modified rosin, or modL. fied rosin ester with a'solvent which is ,a selective solvent for the color bodies ofrosin, separating theselectivesolvent from the undissolved com ponent of the modified rosin or rosin ester and recovering the component of the modified rosin,

dissolved therein, as, for example, by evaporating; the: selective solvent. This process can be repeatedas: manytimes as necessary to produce the desired separation of thecomponents.

l'nxcarrying out this method, themodified rosins I or rosin esters may or may notbefirst dissolved:

cedure in accordance with this invention willv consist. of dissolving themodified rosin or modified rosin. ester in the solvent, contacting the solution soformed with a selective rosin colorbody solvent immiscible therewith, separating the" two 'solutions thus formed, and recovering a component of the modified rosin or modified rosin ester from each. solution as, for example, by evaporating the respective solvents, preferably under reduced pressure. This procedure may be repeated as many times as desired;

Aft-er separating the modified rosin or'modified rosin ester into components by the above procedure, each component may be further'purlfied by crystallization from. suitable solvents, fractionationunder reduced pressure; contacting with an absorbent, such as, fullers earth, kieselguhr; activated carbon, etc. i

The modified rosin or modified rosin ester which I may treat in accordance with this invention may be" any rosin or rosin ester which has beentreated to modify its chemical structure, so that the resultantproduct is a mixture of two ormore chemically difierent substances. The hydrogenation of rosin or' a rosin ester in the'presence ofa suitable catalyst according to methods known to the art produces such a modi fied rosin or modified rosin ester. The esterification of a hydrogenated rosin, likewise, produces such an ester.

The polymerization of rosin or a rosin ester to increase its molecular weight and melting point by treatment with a polymerizingv agent, for" example, volatile metal halides, as, boron trifluoride;

zinc chloride, stannic chloride, aluminum" chloride, ferric chloride;v mineral acids',.as, suliuric acid, phosphoric acid; fullers earth; hydrogen fluoride; acid salts, as sodium acid sulfate, etc.

metallic silicon;hydro'fiuoro-boric acid etc;, ac-

cording. to methods known to the art, produces such, a modified rosin or modified rosin ester. Such a modified rosin ester may also be produced by esterifying apolymerized rosin.

Again, the treatment of rosin or a rosin este with a suitable-catalyst, as,ffor example, ahydrogenation catalyst, as nickel; nickel chromite, platinum, palladium, etc., at an elevated temperature of, for example, from about 150 C. to about 200 C. and without reaction between the rosin or rosin ester and any added substance, to produce an intraand inter-molecular rearrangement within the hydrocarbon nucleus of the rosin or rosin ester with a reduction in the apparent unsaturation as disclosed in the copending application of Edwin R. Littmann, Serial No. 84,877, filed June 12, 1936, produces a modified rosin or modified rosin ester which may be treated in accordance with this invention. Such modified rosins and modified rosin esters will hereinafter be termed Hyex rosins and Hyex rosin esters, respectively. The esterification oi a Hyex rosin also produces such a chemically modified rosin ester.

The modified rosins which I treat in accordance with this invention may be any grade of wood or gum rosin which has been treated to modify its chemical structure so that the product is a mixture of two or more chemically different materials. The esters of the modified rosins which I treat may be produced by the esterification of modified resins or may be produced by the chemical modification of ordinary esters of rosins, and may be esters of either a monohydric or a polyhydric alcohol. Thus, esters of rosins with monohydric alcohols, such as, for example, methanol, ethanol, propanol, butanol, amyl alcohol, cetyl alcohol, lauryl alcohol, stearyl alcohol, furfuryl alcohol, hydrofurfuryl alcohol, abietanol, hydroabietanol, phenol, benzyl alcohol, etc., or with polyhydric alcohols, such. as, for example, ethylene glycol, diethylene glycol, triethylene glycol, glycerol, sorbitol, mannitol, erythritol, pentaerythritol, etc., may be treated by my new method.

The selective solvent which I use in accordance with this invention may be any of the various selective solvents for the visible and latent color bodies of rosins and rosin esters heretofore known.

" Thus, I may use furiural, furfuryl alcohol, a

chlorohydrin, as, ethylene chlorohydrin, propylene chlorohydrin, etc., aniline, phenol, resorcinol, ethyleneglycol, propylene glycol, butylene glycol, diethylene glycol, trimethylene glycol, glycerol, butyl glycerol, ethyl formate, methyl acetate, methyl formats, methyl orthonitrobenzoate, methyl furoate, alkyl formate, monoacetin, diacetin, triacetin, ethylene glycol monoacetate, methanol, hydroxyl alkyl amine, as triethanolamine, a solution of oxalic acid in water or in methanol, ethanol or other lower aliphatic alcohol, ethylene glycol monoethyl ether, or other immisci le glycol ether, ethylene glycol monoacetate, or other immiscible glycol ester, methyl thiocyanate, ethyl thiocyanate, acetonitrile, acetic acid, acetic anhydride, p-chloroaniline, resorcinol plus hydrosulphite, ethylene glycol diacetate, glycerol diacetate, resorcinol monoacetate, resorcinol diacetate, phenyl acetate, furfuryl acetate, ethylidine diacetate, n-propyl furoate, ethyl glycollate, methyl citrate, ethyl tartrate, ethyl malonate, methyl maleate, dimethyl phthalate, benzyl formate, monobutyrin, ethyl carbonate, methyl lactate, diethyl oxalate, methyl adipate, hydroxyhydroquinone triacetate, methyl chlorocarbonate, propylene glycol monoacetate, hydroquinone diacetate, catechol monoacetate, guaiacyl acetate, methyl glutarate, ethyl oxalate; benzyl acetate, diethyl glutacoate, ethyl lactate, diethyl phthalate, ethyl anisate, methyl salicylate, methyl cinnamate, methyl mandelate, methyl acrylate, ethyl oxamate, methyl succinate, ethyl propiolate, ethyl malate, methoXy-benzaldehyde, guaiacol,

I anisidin, nitroanisol, dichloroethyl ether, methoxy acetic acid, methoxybenzyl alcohol, liquid sulfur dioxide, nitromethane, etc., or mixtures of such refining agents which are chemically non-reactive, etc.

The solvent in which I may dissolve the modified rosin or modified rosin ester before contacting it with a selective solvent may be any solvent for the modified rosin or modified rosin ester which is immiscible and non-reactive with the selective solvent used. Thus, I may use a petroleum hydrocarbon solvent, such as, for example, gasoline, petroleum ether, a normally gaseous petroleum hydrocarbon held in liquid phase by elevated pressure, low temperature, or both. The concentration of the modified rosin or modified rosin ester in such a solution may be within the range of about 5% to about by weight, and desirably within the range of about 15% to about 30% by weight.

The temperature at which the process in accordance with my invention may be. carried. out is dependent upon the selective solvent employed and will be within the range of about -40 C. to about +60 C. In any case the temperature used will be such that the selective solvent is a liquid under the pressure used.

In the embodiment of my process in which a chemically modified rosin or a chemically modified rosin ester is dissolved in a solvent therefor before it is contacted with a selective solvent, the solution so formed may have a concentration within the range of about 5% to about 40%, by weight. Usually I prefer to use a solution having a concentration within the range of about 10 to about 25% by weight.

The number of washes employed in my process may be varied in accordance with the results desired, and it will be appreciated that the greater the number of washes given the sharper will be the separation of the components of the chemically modified rosin or chemically modified rosin ester treated.

As illustrations of the practical adaptation of the method in accordance with this invention, I may cite the following:

EXAMPLE I Wood rosin polymerized by treatment in solution in ethylene dichloride solution with aluminum chloride, washed with hydrochloric acid and then with water, and recovered by evaporation of the solvent was treated. One hundred grams of this polymerized rosin was dissolved in 300 grams of gasoline. This solution was washed with '75 cc. of furfural, with 25 parts by volume of iurfural and then with two portions of 10 cc. of furfural. The furfural wash solutions were combined and evaporated to recover the component of the polymerized rosin dissolved therein. Likewise, the gasoline solution was evaporated to recover the component remaining therein.

The two components thus separated from the original polymerized rosin and a sample of the original polymerized rosin were tested by making them into core oils and observing the time required for the core oil to crystallize. The core 011 made from the original polymerized rosin had crystallized in about days, showing'it to be non-crystalline. The component of the polymerized rosin recovered from the gasoline solution after treatment with furfural crystallized from core oil in five days showing it to he unpolymerized rosin. On the other hand, the component of the original polymerized rosin recovered from the furfural had not crystallized from core oil in one hundred and forty days, as compared with about one hundred and five: days for the original polymerized rosin, showing it: to-be more highly polymerized than the original rosin. These'core oil tests demonstrate that the process in accordance withthisinvention separatedthev rosin polymerized by treatment. with. aluminum chloride, intotwo components one of which is a highly polymerized and the other an ordinary unpolymerized rosin. I

EXAMPLE II stock'solut iorr was prepared which contained- 25 of rosin. Therosinpresent-in-thisisolution 'Was composed oi"50% I wood rosin and 50% I wood rosin hydrogenated: to the extentof 50 of the theoretical for two double bonds. Threeportions of this stock solution'of 200 cc. each were counter-currently Washed with three portions of 2007-00. of furfural at room temperature, so that the spent furiura'l'from the first stage successive- 1y passed on to stage 2i and finally stage 3. The three furfuralwashed gasoline solutions, and the three furfnial solutions, were evaporated to] recover the rosin components dissolved therein. The various components thnssecured were analyzed with the results given in Table l which An inspection of the above example shows'that the original blended rosin having a 32% hydro-- genation was separated I into fractions which ranged frorn' 5.6% hydrogenation to 65.5% hydrogenation. The yields in'Tablel show the per cent rosin recovery from each gasoline solution and the per cent recovery from the combined furfural solutions of the total rosin treated.

EXAMPLE III A. hydrogenated I wood rosin saturateclto the extent of 66% was used inthis experiment. Three portions of" 36-0 grains each were counter-cure rently washed with five portions of 100 cc..each of furfural. The resulting'gasoline solutionsand the combined furfural solutions-were evaporated under reduced pressure.- The products thus secured showed'the following results on analysis:

Table .2,

Reiractive Hydroindex genation yleld 5 Percent Percent Original hydrogenated rosin 1. 5255 f 60 Fraction from gasoline sol. No 1 1. 5218 78 44. 5 Fraction from gasoline 501. No. 2 1. 5230 74 66. 2 Fraction from gasoline sol. No. 3;; 1v 5243 68 81. 1 Fraction from combined furfural fractions 1. 538 22 An inspection of the above table shows that the furfural wash removed unhydrogenated or slightly hydrogenated rosin from the hydro genated rosin contained in the gasoline solution, so that the saturation of'the-hydrogenatecl" physical properties:

rosin recovered from the gasoline solution was increased to as highas 78%. As a comparison it will be noted that the rosin recovered from the furfural was saturatedto'the extent only of 22%. The yields in Table 2 show the percent rosin recoveryfrom each gasoline solution.

EXAMPLE IV A gasoline solution containing. 13% I-Iyex wood rosin was prepared. Three p-ortionsof this solution, each 300 parts by volume, were countercurrently. washed with one portion of 50' parts" by volume and six portions of 25 parts by volume, respectively, of 85% aqueous phenol, whereby each rosin solution received four washes. The gasoline solutions, and the com.- bined phenol solutions were evaporated under reduced pressure to recover the rosin fractions dissolved therein. Analysis of the products so recovered showed them to have the following Table 3 Drop Refrac-' S melting tive l 6 Yield point index rotation C. Percent Original Hyex rosin 83 115426 Fraction from gasoline sol. 1 72 1. 5375 +52. 3 17. 5 Fraction from gasoline s01. 2 78 1. 5376 +53. 4 22. 5 Fraction from gasoline w sol. 3 80.5 1. 5400 +554 31. 5 Fraction from aqueous phenol 86. 1. 539 +61. 4 21. 6

An examinationof the above table shows the treatment separated the" original Hyex rosin. into two components havingquite different physical characteristics from one another. A comparison of the properties of the component-from.

gasoline solution 3 and those of the component from the aqueous phenol brings this out. Thus,

the aqueous phenol component had a. definitely higher melting point, a lower refractive index,

and a higher specific rotation, than the fraction from the gasoline solution.

EXAMPLE V Agasoline solution containing 20% Hyex rosin was prepared. Three portions of 300 parts by volume each of the solution were countercurrently washed with one portion of furfural of fifty parts by volume and four portions of furfural of thirty parts by volume, so that each of the gasoline solutions received four countercurrent Washes. The gasoline solutions and the combined furfural wash solutions were evaporatedunder reduced pressure, and the properties of the rosin components recovered determined by analysis. Their characteristics are given in Table 4 which follows;

' TabZe 4 Spe- Drop Refracmelting i tive :35; Yield' point index tion Fraction from gaso- C'. Percent line 1 75. 5 156.5 1.5371 +50.0 21.6 Fraction from gasoline sol. 2 77. 5 160.5 1. 5378 +54. 5 25. 6, Fraction from gasolines .3 82.0 163.0 1.5382 +53.4 32.8 Fraction from furfural S0] 90.0 161.5 1.5527 +60. 2 v 1512 In the above Table has inTable 3' of Exfractions having saturations within the range ample IV, the characteristics of the separated components show them to be different types of rosin.

EXAMPLE VI Three portions of a solution of hydro genated I grade wood rosin in gasoline of 200 grams each were counter-currently washed with methyl thiocyanate at C., so that each gasoline solution received five washes with 20 cc. of methyl thiocyanate. The three refined gasoline solutions and the combined thiocyanate solutions were evaporated under reduced pressure to recover the rosin fractions dissolved in each. The analyses and yields of these fractions of the hydrogenated rosin, as well as that of the original hydrogenated rosin, are given in Table 5 which follows:

Table 5 Refrac- Percent Yleld tive hydromdex genatmn Grams Percent Original hydrogenated rosin l. 5262 62. 5 Rosin from gasoline sol. 1 1. 5230 72 26 21. 9 Rosin from gasoline sol. 2.. 1.5253 67 38. 5 32 Rosin from gasoline sol. 3.. 1. 5248 69 42. 0 35 Rosin from combined methyl thiocyanate wash s01 1 5335 11.5 9.6

An inspection of the data of Table 5 shows that the treatment with the methyl thiocyanate solution separated the hydrogenated rosin having a saturation of 62.5% of theoretical into of 67-72% of theoretical on one hand and 30% of theoretical on the other. Thus, the thiocyanate tended to selectively dissolve unhydrogenated rosin from the more highly hydrogenated rosin which remained in the gasoline solution.

EXAMPLE VII Three portions of a 20% solution of dihyroabietyl alcohol in gasoline of 50 grams each were counter-currently washed with methyl thiocyanate at 0 0., so that each gasoline solution received five washes with 10 cc. portions of methyl thiocyanate. The three refined gasoline solutions and the combined thiocyanate solutions were evaporated under reduced pressure to recover the dissolved fractions. The analyses and yields of these fractions of the dihydroabietyl alcohol are given in Table 6.

Table 6 Weight Hydroxyl Alcohol recovered D. H. A.

Percent Percent Grams Original dihydroabietyl alchol 4. 75 81 Dihydroabietyl alcohol from gas. sol.

No. 1- 4.4 43 0. 7 Dihydroabietyl alcohol from gas.

sol. No. 2 4. 65 60 2. 0 Dihydroabietyl alchol from gas. sol.

No. 3 4. 7 8O 11. 8 Dihydroabietyl alcohol combined methyl thiocyanate sol 4. 8 91.5 12. 3

An inspection of the data of Table 6 shows that the original sample of dihydroabietyl alcohol was 81% alcohol, while the fraction recovered from the combined methyl thiocyanate solution was 91.5% dihydroabietyl alcohol. As compared with this the fraction recovered in the No. l gasoline solution was only 75% dihydroabietyl alcohol. Thus, the treatment in accordance with this invention definitely concentrated the alcoholic portion of the original dihydroabietyl alcohol in the methyl thiocyanate fraction.

EXAMPLE VIII Three portions of 100 grams each of a 20% solution of dihydroabietyl alcohol in gasoline were washed counter-currently with aniline. at 0 C., so that each gasoline solution received five washes with 10 cc. portions of aniline. The three refined gasoline solutions and also the combined aniline solutions were evaporated under reduced pressure to recover the dissolved prod- An examination of the above data shows that aniline, like the methyl thiocyante of the EX- ample V11 selectively dissolved the dihydroabietyl alcohol, yielding a fraction which was materially purer than the original sample.

EXAMPLE IX A glycerol ester of hydrogenated wood rosin (hydroabietic acid) was dissolved in gasoline to a 20% concentration. Three portions of 200 cc. each of this 20% solution were counter-currently washed at 25 C. so that each portion received six washes with 20 cc. portions of 85% phenol. The three refined gasoline solutions and the combined phenol solutions were evaporated under reduced pressure. The analyses and yields of the fractions thus recovered are given in Table 8.

Table 8 Refractive index at Yield Grams Original glycerol ester 1.5303 Ester from gas. 501. No. l l. 5303 '25 Ester from gas. sol. No. 2 1. 5305 Ester from gas. sol. N o. 3 1.5314 37 Ester from combined phenol extract 1. 5316 Since it is known that the less saturated products have higher refraction indices, a comparison of the refractive index of the original ester with that of the fraction secured from the combined phenol extract shows that the latter contains less saturated material than the original, and is a definitely difierent material.

EXAMPLE X The methyl ester of hydrogenated wood rosin (dihydroabietic acid) was treated following exactly the same procedure as in Example IX with the exception that furfural, instead of 85% phenol, was used as a selective solvent. The analyses and yields of the recovered fractions of the ester are given in Table 9.

An. examination of the data given in Table 9 shows that the hydrogenated abietyl ester was concentrated in the gasoline solution #1 while the unhyd ogenated ester was concentrated in the furfural extract.

EXAMPLE XI The glycerol ester of Hyex wood rosin was dissolved in gasoline to produce a 20% solution. Three portions of 200 grams each of this solution were counter-currently Washed with furfural at room temperature (25 C.) so that each portion received washes with six 20 cc. portions of furfural. The gasoline solutions and the combined furfural washes were then evaporated under reduced pressure. Theanalyses and yields of the recovered products are given in Table 10.

Table 10 Refractive 4 index Yield Grams Orig. glyceryl ester of Hyex rosin .i 1.5442 Ester from gas. sol. No. l 1 5432 25 Ester from gas. sol. No. H 1 5435 38 Ester from gas. sol. No. 1 5454 39 Ester from combined furfural ext i l, 6552 21 A comparison of the refractive indices of the original ester, the fraction recovered from the #1 gasoline solution and the fraction recovered from. the furfural solution, shows that the original ester of I-Iyex rosin has been separated into two chemically difierentfractions by the furfural wash.

It will be understood that the above examples and details of operation are given, by way of illustration only, and that the scope of my invention as herein broadly described and claimed is in no way limited thereby.

This application forms a division of my application, Serial No. 160,725,1iled August 24, 1937, entitled Separation of I chemically modified rosins and their esters into components.

What I claim and desire tonprotect byLetters Patent is: v

' 1. The method of separating a chemically modified rosin ester into its components, which comprises dissolving the said chemically modified rosin ester in a solvent therefor, contacting the solution so formed with a selective rosin color:

body solvent immiscible with the said solution,

separating the selective solvent therefrom and recovering a component or" the chemically modified rosin ester from each of the resulting solutions.

2. The method of separating a chemically mod-'- ified rosin ester into its components, which comprises dissolving the said ,chemically modified rosin ester in a solvent therefor, contacting the solution so formed-with a selective rosin colorbody solvent immiscible with the said solution,

separating the selective solvent therefrom and recovering a component of the chemically modified rosin ester from each of the resulting solutions by evaporating the solvent.

3. The method of separating a chemically modified rosin ester into its components, which comprises dissolving the said chemically modified rosin ester in a petroleum hydrocarbon solvent, contacting thesolution so formed with a selective color-body solvent immiscible with the said solution, separating the selective solvent therefrom and recovering a component of the chemically modified rosin ester from each of the re- I suiting solutions by evaporating the solvent.

4.. The method of separating a chemically modified rosin ester into its components, which comprises dissolving the said chemically modified rosin ester in a solvent therefor, contacting the solution-"so formed with furfural, separating the furfural therefrom and recovering'a component of the chemically modified rosin ester from each of the resulting solutions by evaporating the solvent. I

5. The method of separating a chemically modified rosin ester into its components, which comprises dissolving the said chemically modified rosin ester in a solvent therefor, contacting the solution so formed with phenol, separating the phenol therefrom and recovering a component of the chemically modified rosin ester from each of the resulting solutions by evaporating the solvent.

6. The method of separating a chemically modified rosinester into its components, which comprises dissolving the said chemically modified rosin ester in a solventtherefor, contacting the solution so formed with an alkyl thiocyanate, separating the alkyl thiocyanate therefrom and recovering a component of the chemically modified rosin ester from each of the resulting solutions by evaporating the solvent.

7. The method of separating a chemically mod ified rosin ester into its componentsywhich comprises dissolving the said chemically modified rosin ester in a petroleum hydrocarbon solvent, contacting the solution so formed with furfural, separating the furfural therefrom and recovering a component of the chemically modified rosin prises dissolving the hydrogenated rosin ester in a petroleum hydrocarbon solvent, contacting the solution so formed with a selective rosin colorbody solvent immiscible with the said solution,"

separating the selective solvent therefrom and recovering a component of the hydrogenated rosin ester from each of the resulting solutions by evaporating the solvent. 7

10. The method of separating an ester of hydrogenated rosin into its components which comprises dissolving the hydrogenated rosin ester in a petroleum hydrocarbon solvent, contacting the solution so formed with furfural, separating the .furfural therefrom and recovering a component of the hydrogenated rosin ester from each of the resulting solutions by evaporating the solvent.

11. The method of separating a chemically modified rosin ester into its components", which comprises dissolving the said chemically modified rosin ester in a petroleum hydrocarbon solvent, contacting the solution so formed with phenol, separating the phenol therefrom and recovering a component of the chemically modified rosin ester from each of the resulting solutions by evaporating the solvent.

12. The method of separating a chemically modified rosin ester into its components, which comprises dissolving the said chemically modified rosin ester in a petroleum hydrocarbon solvent, contacting the solution so formed with an alkyl thiocyanate, separating the alkyl thiocyanate therefrom and recovering a component of the chemically modified rosin ester from each of the resulting solutions by evaporating the solvent.

13. The method of separating an ester of hydrogenated rosin into its components which comprises dissolving the hydrogenated rosin ester in a petroleum hydrocarbon solvent, contacting the solution so formed with phenol, separating the phenol therefrom and recovering a component of the hydrogenated rosin ester from each of the resulting solutions by evaporating the solvent.

14. The method of separating an ester of hydrogenated rosin into its components which 'comprises dissolving the hydrogenated rosin ester in a petroleum hydrocarbon solvent, contacting the solution so formed With an alkyl thiocyanate, separating the alkyl thiocyanate therefrom and recovering a component of the hydrogenated rosin ester from each of the resulting solutions by evaporating the solvent.

15. The method of separating a glycerol ester of hydrogenated rosin into its components, which comprises dissolving the said ester in a petroleum hydrocarbon solvent, contacting the solution so formed with furfural, separating the furfural therefrom and recovering a component of the material from each of the resulting solutions by evaporating the solvent.

JOSEPH N. BORGLIN. 

